Low Pressure Omcvd Growth of GaAs on InP for Fet and Quantum Well Laser Fabrication

1989 ◽  
Vol 145 ◽  
Author(s):  
R. Bhat ◽  
Y-H. Lo ◽  
C. Caneau ◽  
C.J. Chang-Hasnain ◽  
B.J. Skromme ◽  
...  
Keyword(s):  
Quantum Well ◽  
Field Effect Transistors ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Single Quantum Well ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Buried Heterostructure ◽  
Step Growth ◽  
Inp Substrates

AbstractGallium arsenide epitaxial layers with excellent morphology have been grown by organometallic chemical vapor deposition (OMCVD) on (100) and 2-3° off (100) InP substrates by a modified two-step growth commonly used for GaAs on Si. The layers have been characterized by X-ray diffraction, cross-sectional transmission electron microscopy (TEM), low temperature photoluminescence (PL) and Hall measurements. 1 µm gate GaAs metal-semiconductor field effect transistors (MESFETs) with transconductances as high as 220 mS/mm have been fabricated. These MESFETs have been integrated with buried heterostructure and V-groove InGaAsP lasers. The V-groove laser -MESFET OEIC transmitter has been shown to be capable of direct modulation at 5 Gb/sec bit rate. Finally we have also demonstrated GaAs single quantum well lasers with threshold currents as low as 800 A/cm2for 50 µm wide broad area gain guided devices with 1.25 mm long cavities.

The Characterization Of Chemical Bath Deposited Cds On Single Crystal InP Substrates

1997 ◽  
Vol 485 ◽  
Author(s):  
G. M. Riker ◽  
M. M. Al-Jassim ◽  
F. S. Hasoon
Keyword(s):  
Electron Microscopy ◽  
Single Crystal ◽  
Surface Cleaning ◽  
Film Morphology ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Fine Grained ◽  
Transmission Electron ◽  
Cds Thin Films ◽  
Inp Substrates

AbstractWe have investigated CdS thin films as possible passivating window layers for InP. The films were deposited on single crystal InP by chemical bath deposition (CBD). The film thickness, as optically determined by ellipsometry, was varied from 500 to 840Å. The film morphology was investigated by high resolution scanning electron microscopy (SEM), whereas the film microstructure was studied by X-ray diffraction (XRD) and cross-sectional transmission electron microscopy (TEM). Most of the films were fine-grained polycrystalline CdS, with some deposition conditions resulting in epitaxial growth. Cross-sectional TEM examination revealed the presence of interface contaminants. The effect of such contaminants on the film morphology and microstructure was studied, and various approaches for InP surface cleaning/treatment were investigated. The epitaxial films were determined to be hexagonal on both the (111) and (100) InP substrates; however, they were heavily faulted.

Spontaneous Lateral Modulations in InAlAs Buffer Layers Grown by MBE on InP Substrates

1995 ◽  
Vol 417 ◽  
Author(s):  
F. Peiró ◽  
A. Cornet ◽  
J. C. Ferrer ◽  
J. R. Morante ◽  
G. Halkias ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
Buffer Layers ◽  
Single Quantum ◽  
X Ray Diffraction ◽  
Single Quantum Well ◽  
Quantum Well Structures ◽  
X Ray ◽  
Transmission Electron ◽  
Inp Substrates

AbstractTransmission Electron Microscopy (TEM) and X-ray Diffraction (XRD) have been used to analyze the spontaneous appearance of lateral composition modulations in InyAl1−yAs (yIn.≅ 50%) buffer layers of single quantum well structures grown by molecular beam epitaxy on exact and vicinal (100) InP substrates, at growth temperatures in the range of 530°C–580°C. The influence of the growth temperature, substrate misorientation and epilayer mismatch on the InAlAs lateral modulation is discussed. The development of a self-induced quantum-wire like morphology in the In0.53Ga0.47As single quantum wells grown over the modulated buffers is also commented on.

scholarly journals Structural Property Study for GeSn Thin Films

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3645
Author(s):  
Liyao Zhang ◽  
Yuxin Song ◽  
Nils von den Driesch ◽  
Zhenpu Zhang ◽  
Dan Buca ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Threading Dislocations ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron

The structural properties of GeSn thin films with different Sn concentrations and thicknesses grown on Ge (001) by molecular beam epitaxy (MBE) and on Ge-buffered Si (001) wafers by chemical vapor deposition (CVD) were analyzed through high resolution X-ray diffraction and cross-sectional transmission electron microscopy. Two-dimensional reciprocal space maps around the asymmetric (224) reflection were collected by X-ray diffraction for both the whole structures and the GeSn epilayers. The broadenings of the features of the GeSn epilayers with different relaxations in the ω direction, along the ω-2θ direction and parallel to the surface were investigated. The dislocations were identified by transmission electron microscopy. Threading dislocations were found in MBE grown GeSn layers, but not in the CVD grown ones. The point defects and dislocations were two possible reasons for the poor optical properties in the GeSn alloys grown by MBE.

Heteroepitaxial Bi2Sr2CaCu2Ox Superconducting thin films Deposited on LaA1O3 by Solid Phase Epitaxy and OMCVD

1992 ◽  
Vol 275 ◽  
Author(s):  
J. Chen ◽  
H. A. Lu ◽  
F. DiMeo ◽  
B. W. Wessels ◽  
D. L. Schulz ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Superconducting Thin Films ◽  
Epitaxial Thin Films ◽  
Solid Phase Epitaxy ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Film Substrate

ABSTRACT-Heteroepitaxial superconducting Bi,Sr2CaCu2Ox (BSCCO 2212) thin films have been formed by solid phase epitaxy from amorphous films deposited on (100) LaA1O3 single crystal substrates by organometallic chemical vapor deposition. The epitaxial structure of the film is confirmed by x-ray diffraction including θ/2θ and Φ (in plane rotation) scans. Cross-sectional high resolution transmission electron microscopy indicates that the film-substrate interface is nearly atomically abrupt. Improvements in superconducting properties of the epitaxial thin films are noted in comparison to highly textured films deposited on MgO.

Highly oriented diamond growth on positively biased Si substrates

2001 ◽  
Vol 16 (12) ◽  
pp. 3351-3354 ◽  
Author(s):  
Te-Fu Chang ◽  
Li Chang
Keyword(s):  
Electron Microscopy ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Plasma Chemical Vapor Deposition ◽  
Si Substrates ◽  
Transmission Electron

Deposition of highly textured diamond films on Si(001) has been achieved by using positively bias-enhanced nucleation in microwave plasma chemical vapor deposition. During the biasing period, an additional glow discharge due to the dc plasma effect appeared between the electrode and the substrate. The discharge is necessary for enhanced nucleation of diamond. X-ray diffraction, scanning electron microscopy, and cross-sectional transmission electron microscopy (XTEM) were used to characterize the microstructure of the diamond films on Si. The results show the morphology of diamond grains in square shape with strong diamond (001) texture. XTEM reveals that an amorphous interlayer formed on the smooth Si surface before diamond nucleation.

SiCOI Structure Fabricated by Hot-Mesh Chemical Vapor Deposition

2006 ◽  
Vol 11-12 ◽  
pp. 257-260
Author(s):  
Kanji Yasui ◽  
T. Kurimoto ◽  
Masasuke Takata ◽  
Tadashi Akahane
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Mesh Structure ◽  
Transmission Electron ◽  
Thermal Oxide ◽  
Ft Ir ◽  
Sic Films

The growth of 3C-SiC on thermal oxide layer of Si (SiO2) was investigated by hot-mesh (HM) chemical vapor deposition (CVD), which utilizes hot tungsten (W) wires of a mesh structure as a catalyzer. The SiC films were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and cross sectional transmission electron microscopy (TEM). From the XRD spectra of SiC films grown on SiO2 layer, (100) oriented SiC films were grown at the substrate temperatures of 750-800°C and the mesh temperature of 1600°C, while polycrystalline SiC films were grown at the substrate temperature above 900°C. From the data of FT-IR, TEM and the growth rate, the growth characteristics of SiC crystal by HMCVD were discussed.

TEM evaluation of graded SixGe1-x heterolayers

1991 ◽  
Vol 49 ◽  
pp. 894-895
Author(s):  
N. David Theodore ◽  
Mamoru Tomozane ◽  
Ming Liaw
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Gas Flow ◽  
Field Effect Transistors ◽  
Chemical Vapor ◽  
Dark Field ◽  
Bipolar Transistors ◽  
Structural Quality ◽  
Weak Beam ◽  
Transmission Electron ◽  
And Behavior

There is extensive interest in SiGe for use in heterojunction bipolar transistors. SiGe/Si superlattices are also of interest because of their potential for use in infrared detectors and field-effect transistors. The processing required for these materials is quite compatible with existing silicon technology. However, before SiGe can be used extensively for devices, there is a need to understand and then control the origin and behavior of defects in the materials. The present study was aimed at investigating the structural quality of, and the behavior of defects in, graded SiGe layers grown by chemical vapor deposition (CVD).The structures investigated in this study consisted of Si1-xGex[x=0.16]/Si1-xGex[x= 0.14, 0.13, 0.12, 0.10, 0.09, 0.07, 0.05, 0.04, 0.005, 0]/epi-Si/substrate heterolayers grown by CVD. The Si1-xGex layers were isochronally grown [t = 0.4 minutes per layer], with gas-flow rates being adjusted to control composition. Cross-section TEM specimens were prepared in the 110 geometry. These were then analyzed using two-beam bright-field, dark-field and weak-beam images. A JEOL JEM 200CX transmission electron microscope was used, operating at 200 kV.

scholarly journals Temperature Dependence of Stress and Optical Properties in AlN Films Grown by MOCVD

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 698
Author(s):  
Wenwang Wei ◽  
Yi Peng ◽  
Jiabin Wang ◽  
Muhammad Farooq Saleem ◽  
Wen Wang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Compressive Stress ◽  
Sapphire Substrate ◽  
Light Transmission ◽  
Chemical Vapor ◽  
Biaxial Stress ◽  
X Ray Diffraction ◽  
Patterned Sapphire Substrate ◽  
Transmission Electron ◽  
Nano Patterning

AlN epilayers were grown on a 2-inch [0001] conventional flat sapphire substrate (CSS) and a nano-patterned sapphire substrate (NPSS) by metalorganic chemical vapor deposition. In this work, the effect of the substrate template and temperature on stress and optical properties of AlN films has been studied by using Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible spectrophotometer and spectroscopic ellipsometry (SE). The AlN on NPSS exhibits lower compressive stress and strain values. The biaxial stress decreases from 1.59 to 0.60 GPa for AlN on CSS and from 0.90 to 0.38 GPa for AlN on NPSS sample in the temperature range 80–300 K, which shows compressive stress. According to the TEM data, the stress varies from tensile on the interface to compressive on the surface. It can be deduced that the nano-holes provide more channels for stress relaxation. Nano-patterning leads to a lower degree of disorder and stress/strain relaxes by the formation of the nano-hole structure between the interface of AlN epilayers and the substrate. The low crystal disorder and defects in the AlN on NPSS is confirmed by the small Urbach energy values. The variation in bandgap (Eg) and optical constants (n, k) with temperature are discussed in detail. Nano-patterning leads to poor light transmission due to light scattering, coupling, and trapping in nano-holes.

Low Temperature Large Scale CVD Synthesis of Nano Onion-Like Fullerenes

2012 ◽  
Vol 490-495 ◽  
pp. 3211-3214 ◽  
Author(s):  
Lei Shan Chen ◽  
Cun Jing Wang
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Aluminum Hydroxide ◽  
Large Scale ◽  
Iron Catalyst ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Naoh Solution ◽  
Synthesis Reactions

Synthesis reactions were carried out by chemical vapor deposition using iron catalyst supported on aluminum hydroxide at 400 °C and 420 °C, in the presence of argon as carrier gas and acetylene as carbon source. The aluminum hydroxide support was separated by refluxing the samples in 40% NaOH solution for 2 h and 36% HCl solution for 24 h, respectively. The samples were characterized by field-emission scanning electron microscopy, energy dispersive spectroscopy, high-resolution transmission electron microscopy and X-ray diffraction. The results show that carbon nanotubes were the main products at 420 °C, while large scale high purity nano onion-like fullerenes encapsulating Fe3C, with almost uniform sizes ranging from 10-50 nm, were obtained at the low temperature of 400 °C.

scholarly journals Fabrication and Physical Properties of Single-Crystalline Βeta-FeSi2 Nanowires

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Chih-Yung Yang ◽  
Shu-Meng Yang ◽  
Yu-Yang Chen ◽  
Kuo-Chang Lu
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Field Emitters ◽  
Transmission Electron ◽  
Single Source Precursor ◽  
Carrier Gases

Abstract In this study, self-catalyzed β-FeSi2 nanowires, having been wanted but seldom achieved in a furnace, were synthesized via chemical vapor deposition method where the fabrication of β-FeSi2 nanowires occurred on Si (100) substrates through the decomposition of the single-source precursor of anhydrous FeCl3 powders at 750–950 °C. We carefully varied temperatures, duration time, and the flow rates of carrier gases to control and investigate the growth of the nanowires. The morphology of the β-FeSi2 nanowires was observed with scanning electron microscopy (SEM), while the structure of them was analyzed with X-ray diffraction (XRD) and transmission electron microscopy (TEM). The growth mechanism has been proposed and the physical properties of the iron disilicide nanowires were measured as well. In terms of the magnetization of β-FeSi2, nanowires were found to be different from bulk and thin film; additionally, longer β-FeSi2 nanowires possessed better magnetic properties, showing the room-temperature ferromagnetic behavior. Field emission measurements demonstrate that β-FeSi2 nanowires can be applied in field emitters.

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